1. Technical Field
The present invention relates to a method for reducing the amount of asparagine, a precursor of acrylamide, in a food product. More specifically, this invention relates to increasing the stability of the enzyme asparaginase in a solution.
2. Description of Related Art
As discussed in U.S. Pat. No. 7,037,540, acrylamide has been found in thermally-processed foods containing asparagine. The level of acrylamide formed in some food products can be reduced by adding the enzyme asparaginase to the food product prior to cooking the food product.
The addition of acrylamide reducing enzymes such as asparaginase to food products on a commercial scale, as opposed to a batch scale, presents several challenges. For example, the enzyme asparaginase must contact free asparagine to facilitate the hydrolysis of asparagine. As the enzyme is typically supplied in a relatively concentrated form, the enzyme is ideally mixed and diluted in a water-based solution prior to contacting the food product with the enzyme solution. For example, contacting the food product with the enzyme solution can comprise forming a dough and admixing an enzyme solution with the dough.
A known way to quantify the activity of an enzyme is by referring to the enzyme in terms of units. One unit of enzyme activity is defined as the amount of enzyme required as a catalyst to convert one micromole of substrate in one minute. Thus, knowing the relative concentration of a substrate or compound such as asparagine in a food product, and the amount of food product, one can calculate the units of enzyme, such as asparaginase, required to convert the desired chemical compound, in this case, asparagine, into a different chemical compound.
For previously unknown reasons, even when excess doses (meaning more than the mathematically expected amount required to convert all the asparagine in the food product) of the asparaginase enzyme are used in a food product, such as potato mash or corn masa, there oftentimes are still measurable levels of asparagine in the dough. Because it is desired to reduce the level of acrylamide formed when certain foods are thermally processed, it would be desirable to have a system and method of maximizing the effectiveness of an enzyme used to reduce acrylamide pre-cursors in food products made on a commercial scale.